Meeting Abstract
Caribbean Anolis lizards evolved subdigital toepads—similar to those found among geckos—as a key innovation that allowed them to invade a diversity of niches. Like other lizards, anoles have claws, which presumably function in concert with the toepads to aid adhesion when climbing. However, the interactive function of claws with toepads is not well understood in anoles. Having claws and toepads could be beneficial when climbing, by providing a greater diversity of adhesive mechanisms on unpredictable terrain. Conversely, claws may hinder adhesive abilities when moving on smooth surfaces by interfering with the toepad’s contact with the surface. We examined the effects of incline and surface variations on running performance of three anole ecomorphs. Lizards were tested on a level and incline surface tilted at 45°, while covered with nylon mesh facilitating claw use, and while covered with Plexiglas isolating toepad use. We hypothesized that all anole lizards would perform similarly on level surfaces, but the arboreal ecomorphs would be more robust to the treatments on incline surfaces. On the level, no significant differences were found in running speed among ecomorphs regardless of whether they were able to use their claws and/or toepads. Surprisingly, when running on the 45° incline, the trunk-ground anoles (Anolis sagrei and A. cristatellus) seemed to be less affected by running on Plexiglas than the “trunk-crown” ecomorph (A. carolinensis) and trunk anoles (A. distichus). These more arboreal species presented significantly reduced running speeds and slipped while running on the plastic-covered incline. These results suggest that unlike among many geckos, anole claws are critically important for amplifying the adhesive capabilities of the toepad-claw system.
